The new variety of Fraxinus pennsylvanica lanceolata was discovered and selected during August 1987 while growing among Green Ash seedlings at Vegreville, Alberta, Canada. At the time of the discovery, the new variety was present among Green Ash trees planted in the late 1970""s using a hardy seed source from Montana. During the selection it was desired to provide a Green Ash tree that is hardier than the xe2x80x98Patmorexe2x80x99 variety (U.S. Plant Pat. No. 4,684) since severe winter damage and kill has been observed for such variety in the Prairie Provences of Canada. The Calgary area where the selection was made is recognized to be one of the harshest winter climates in North America. Other selection criteria included an attractive growth habit and ovarall tree shape, freedom from seed formation, and attractive glossy leaves. Had the new variety of the present invention not been discovered and preserved it would have been lost to mankind.
It was found that the new variety of the present invention:
(a) Exhibit greater winter hardiness than the xe2x80x98Patmorexe2x80x99 variety,
(b) Forms no seeds,
(c) Forms glossy dark green leaflets having generally less serration than the xe2x80x98Patmorexe2x80x99 variety,
(d) Exhibits when young a generally smoother bark than the xe2x80x98Patmorexe2x80x99 variety,
(e) Exhibits an oval crown that is generally more dense and compact than that of the xe2x80x98Patmorexe2x80x99 variety, and
(f) Is particularly well suited for growing as a street planting or a shade tree in the landscape.
Trees of the new variety were first asexually reproduced by budding on Fraxinus pennsylvanica lanceolata rootstock at Kelowna, British Columbia, Canada. The new variety also has been asexually reproduced at Saint Paul, Minn. The characteristics of the new variety have been found to be strictly transmissible from one generation to another following such asexual reproduction. The plant has proven to be very stable through a number of years of asexual propagation by budding. There have been observed no variants or off types to date.
The new variety has been demonstrated to possess slightly less vigor than the xe2x80x98Patmorexe2x80x99 variety. At a given age the caliper will be approximately the same as the xe2x80x98Patmorexe2x80x99 variety; however, the new variety is shorter and more compact. At times it may be desirable to thin the branches of the new variety to limited extent. The height of the new variety at a given age will tend to be shorter than that of the xe2x80x98Patmorexe2x80x99 variety. The more dense and compact growth habit and generally rounder head of the new variety will convey a superior overall appearance than the more open growth habit of the xe2x80x98Patmorexe2x80x99 variety. The winter hardiness of the new variety has also been found to be significantly greater than that of the xe2x80x98Patmorexe2x80x99 variety.
The new variety of the present invention initially was designated the xe2x80x98Foothillsxe2x80x99 variety. It subsequently has been named the xe2x80x98Heuverxe2x80x99 variety.